| 摘要 |
PURPOSE:To decrease the frequency-temperature coefficient, by selecting the material of the glass substrate. CONSTITUTION:The inter-digital electrode 2 is provided on the glass substrate 1 via an Al thin film, and the ZnO thin film 3 is stuck on the electrode 2 by the sputtering method. Then the counted electrode 4 is formed on the film 3 via the Al film to obtain a ZnO thin-film elastic surface wave element. The substrate 1 uses mainly SiO2 having a component ratio within a range of 0.05<=X/Y<=0.32, where X is the total of mol% of one or plural kinds among Li2O, Na2O, K2O, MgO, CaO and BaO and Y is the total of mol% of one or plural kinds among B2O3, Al2O3, SiO2, ZnO, PbO and TiO2. With use of a glass substrate of such composition, the frequency-temperature coefficient of the elastic surface wave can be set within a range from -30ppm/ deg.C to +30ppm/ deg.C. |
